fix (core): Enable prompt caching for openai-compatible by default un…

packages/opencode/src/provider/transform.ts

@@ -788,8 +788,18 @@ export namespace ProviderTransform {
       }
     }
 
-    if (input.model.providerID === "openai" || input.providerOptions?.setCacheKey) {
+    if (
+      input.model.providerID === "openai" || 
+      (
+        input.model.api.npm === "@ai-sdk/openai-compatible" && 
+        input.providerOptions?.setCacheKey !== false
+      ) ||
+      input.providerOptions?.setCacheKey === true
+    ) {
       result["promptCacheKey"] = input.sessionID
+      if ("setCacheKey" in input.providerOptions) {
+        delete input.providerOptions["setCacheKey"]
+      }
     }
 
     if (input.model.api.npm === "@ai-sdk/google" || input.model.api.npm === "@ai-sdk/google-vertex") {

packages/opencode/test/provider/transform.test.ts

@@ -85,6 +85,35 @@ describe("ProviderTransform.options - setCacheKey", () => {
     expect(result.promptCacheKey).toBe(sessionID)
   })
 
+  test("should set promptCacheKey for openai-compatible provider when setCacheKey not present and setCacheKey not present", () => {
+    const openaiModel = {
+      ...mockModel,
+      providerID: "openai-compatible",
+      api: {
+        id: "gpt-4",
+        url: "https://api.openai.com",
+        npm: "@ai-sdk/openai-compatible",
+      },
+    }
+    const result = ProviderTransform.options({ model: openaiModel, sessionID, providerOptions: {} })
+    expect(result.promptCacheKey).toBe(sessionID)
+  })
+
+  test("should not set promptCacheKey for openai-compatible provider when setCacheKey is false and setCacheKey not present in result", () => {
+    const openaiModel = {
+      ...mockModel,
+      providerID: "openai-compatible",
+      api: {
+        id: "gpt-4",
+        url: "https://api.openai.com",
+        npm: "@ai-sdk/openai-compatible",
+      }
+    }
+    const result = ProviderTransform.options({ model: openaiModel, sessionID, providerOptions: { setCacheKey: false } })
+    expect(result.promptCacheKey).toBeUndefined()
+  })
+
+
   test("should set store=false for openai provider", () => {
     const openaiModel = {
       ...mockModel,